Display system and vehicle
According to one embodiment, a display system includes an external light sensor, a display panel, a viewing angle control panel including a liquid crystal layer containing liquid crystal molecules twist-aligned, configured such that a drive voltage applied to the liquid crystal layer is controlled based on an external light intensity detected by the external light sensor, and a polarization axis rotation element disposed between the viewing angle control panel and the display panel. The drive voltage when the external light intensity is less than a threshold value is greater than the drive voltage when the external light intensity is greater or equal to than the threshold value.
1. A display system comprising:
an optical light sensor detecting a light intensity;
a display panel;
a first polarizer disposed on a front side of the display panel;
a viewing angle control panel comprising a liquid crystal layer containing liquid crystal molecules twist-aligned; and
a polarization axis rotation element disposed between the viewing angle control panel and the display panel, and rotating a polarization axis of light transmitted through the viewing angle control panel, wherein
the liquid crystal molecules twist-aligned include an alignment direction which is substantially parallel to a first transmission axis of the first polarizer,
the viewing angle control panel is configured that a luminance of a transmitted light in the alignment direction decreases as a drive voltage applied to the liquid crystal layer increases, and
the drive voltage when the light intensity is less than a threshold value is greater than the drive voltage when the light intensity is greater than or equal to the threshold value.
2. The display system of claim 1 , further comprising an illumination device incorporating a light-emitting element, and configured to emit illumination light toward the display panel, wherein
a luminance level of the light-emitting element when the light intensity is greater than or equal to the threshold value is equal to the luminance level of the light-emitting element when the light intensity is less than the threshold value.
3. The display system of claim 1 , further comprising an illumination device incorporating a light-emitting element, and configured to emit illumination light toward the display panel, wherein
a luminance level of the light-emitting element when the light intensity is less than the threshold value is greater than the luminance level of the light-emitting element when the light intensity is greater than or equal to the threshold value.
4. The display system of claim 1 , further comprising:
a second polarizer disposed between the display panel and the polarization axis rotation element; and
a third polarizer disposed between the polarization axis rotation element and the viewing angle control panel, wherein
the second polarizer has a second transmission axis,
the third polarizer has a third transmission axis, and
the polarization axis rotation element is configured to impart a retardation of ½ wavelength to a transmitted light, and has an optical axis in a direction halfway between a direction of the second transmission axis and a direction of the third transmission axis.
5. A vehicle comprising:
a front window disposed in a front part of the vehicle;
a driver seat and a passenger seat;
a display device; and
an optical light sensor detecting a light intensity, wherein
the display device comprises:
a display panel;
a first polarizer disposed on a front side of the display panel; and
a viewing angle control panel comprising a liquid crystal layer containing liquid crystal molecules twist-aligned, and
the liquid crystal molecules twist-aligned include an alignment direction which is substantially parallel to a first transmission axis of the first polarizer,
the viewing angle control panel is configured that a luminance of a transmitted light in the alignment direction decreases as a drive voltage applied to the liquid crystal layer increases, and
the drive voltage when the light intensity is less than a threshold value is greater than the drive voltage when the light intensity is greater than or equal to the threshold value.
6. The vehicle of claim 5 , wherein
the driver seat and the passenger seat are arranged in a first direction, and
the alignment direction is substantially orthogonal to the first direction.
7. The vehicle of claim 5 , further comprising an illumination device incorporating a light-emitting element, and configured to emit illumination light toward the display panel, wherein
a luminance level of the light-emitting element when the light intensity is greater than or equal to the threshold value is equal to the luminance level of the light-emitting element when the light intensity is less than the threshold value.
8. The vehicle of claim 5 , further comprising an illumination device incorporating a light-emitting element, and configured to emit illumination light toward the display panel, wherein
a luminance level of the light-emitting element when the light intensity is less than the threshold value is greater than the luminance level of the light-emitting element when the light intensity is greater than or equal to the threshold value.
9. The vehicle of claim 5 , further comprising a polarization axis rotation element disposed between the viewing angle control panel and the display panel, and configured to rotate a polarization axis of light transmitted through the viewing angle control panel.
10. The vehicle of claim 9 , further comprising:
a second polarizer disposed between the display panel and the polarization axis rotation element; and
a third polarizer disposed between the polarization axis rotation element and the viewing angle control panel, wherein
the second polarizer has a second transmission axis,
the third polarizer has a third transmission axis, and
the polarization axis rotation element is configured to impart a retardation of ½ wavelength to a transmitted light, and has an optical axis in a direction halfway between a direction of the second transmission axis and a direction of the third transmission axis.